The subject invention relates to a scanner device for generating a three dimensional (3D) surface model of arbitrarily shaped objects, such as dental structures, preferably applicable for use in the field of stomatology, dentistry, or orthodontics, and particularly to dental prosthetics manufacturing. More specifically, the subject invention includes an intraoral 3D dental scanning device and methods for imaging and visualizing teeth or gingivae surfaces, including the conformation thereof.
Three-dimensional (3D) diagnostic and therapeutic modeling of teeth and gingivae have been traditionally obtained by mainstream techniques, such as using replicas obtained from alginate-impressed molds. Such replicas provide gingiva and tooth negative-image molds, which can later be converted into positive models, which may be scanned. However, these mainstream techniques pose problems and disadvantages which are manifold. These problems include: patient discomfort during the process of creating the mold, creation of imperfections and inaccuracies in the resulting mold, and the process can be slow and costly.
More recently, several state-of-the-art devices have been developed, e.g., panoramic dental X-rays, computerized dental tomographies, and optical scanning devices, that attempt to solve the problems posed by mainstream techniques. Optical scanners are devices which can capture and record information from the surface of an object, and generate that information into an image.
The use of scanners to determine the surface contour of objects by non-contact optical methods has become increasingly important in many applications including the in vivo scanning of dental structures to create a 3D model. Typically, the 3D surface contour is formed from a cloud of points where the relative position of each point in the cloud represents an estimated position of the scanned object's surface at the given point.
Such optical scanning devices have been developed and made commercially available for the dental market, and have been described in the patent literature incorporating a variety of technologies and configurations. For example, certain European patents have been identified as describing scanning devices, such as: EP 0825837, entitled, “Modular intra-oral imaging system video camera,” provides a hand-held video camera to capture images of the inner part of the mouth and an optically aligned sensor which converts the captured images into usable data; ES 2383220, entitled “Intraoral dental imaging sensor and X-ray system, using such sensor,” describes an intraoral dental radiological system equipped with a mouth-insertable X-ray imaging sensor having an image-detection matrix to provide electronic signals, and a light source to receive the matrix-generated signals; and ES 2324658 (T3), entitled “Laser-digitalizing system for dental applications” describes a laser digitizer that has a light source with collimation optics to generate a collimated light beam, a scanner optically coupled with the light source.
Optical scanning devices have also been patented or published in the United States, for example, in U.S. Pat. No. 6,648,640, entitled “INTERACTIVE ORTHODONTIC CARE SYSTEM BASED ON INTRA-ORAL SCANNING OF TEETH”; U.S. Pat. No. 4,837,732, entitled “Method and Apparatus for the Three-Dimensional Registration and Display of Prepared Teeth”; U.S. Pat. No. 4,575,805, entitled “Method And Apparatus For The Fabrication Of Custom-Shaped Implants”; U.S. Pat. No. 5,372,502, entitled “Optical Probe and Method for the Three-Dimensional Surveying of Teeth”; U.S. Pat. No. 5,027,281, entitled “Method and Apparatus for Scanning and Recording of Coordinates Describing Three Dimensional Objects of Complex and Unique Geometry”; U.S. Pat. No. 5,431,562, entitled “Method and Apparatus for Designing and Forming a Custom Orthodontic Appliance and for the Straightening of Teeth therewith”; U.S. Pat. No. 6,592,371, entitled “Method and System for Imaging and Modeling a Three Dimensional Structure”; and U.S. Pat. No. 7,004,754, entitled “Automatic Crown and Gingiva Detection from Three-Dimensional Virtual Model of Teeth”; as well as U.S. Publication No. 2006/0154198, entitled “3D Dental Scanner.”
These systems and devices previously described all have various disadvantages in their design and use in practice. Commercially available 3D scanner systems have been developed for the dental market typically employ a handheld (by the operator), wand-type scanner in communication with a central (and typically large and bulky) computer/power source. In these systems, the operator moves the scanner over the area to be scanned and collects a series of image frames. The intraoral cavity represents a significant challenge for accurate in vivo 3D imaging of the surface of teeth and tissue. The ability to accurately measure the center of a scanning line is affected by the translucency of teeth, the variety of other reflecting surfaces (amalgam fillings, metal crowns, gum tissue, etc.) and the obscuration due to adjacent surfaces. Further, linear or rotational motion adds to error accumulation and the variation in size and curvature of human jaws makes a “one size fits all” scanner problematic.
In addition to the inaccuracies that can be introduced, these state-of-the-art devices and systems can be inconvenient to use, and inconvenient for the patient. In some cases, a technician must manually operate the handheld wand using a toothbrush-like motion and the results can depend on the dexterity and skill of the operator. Systems based on photographs taken by the various devices where software interprets and interpolates the photographic information into a final 3D image, can be time-consuming.
Thus, what is needed in the art is a 3D scanning device, and system, which can address and overcome disadvantages and limitations of the devices and systems which have been previously described and marketed.
The subject invention addresses and overcomes certain disadvantages of prior systems and devices by providing a completely integrated, unitary device, which is portable, and can be easily held by the patient during use. Thus, the invention provides a dental scanning device without certain flaws and inconveniences of the previously known state-of-the-art systems, capturing accurate 3D images using a fixed-reference system. No handheld wand is required, and no manual operation of the scanning probe is necessary by a technician or a patient, as the device and system is fully automated.